A huge storm has finally blown away from Luzon, the main northern Philippine island, leaving at least 20 people dead, forcing 70,000 villagers into emergency shelters, and destroying rice fields ready for harvest. Officials say there is still a danger that rains dumped by Tropical Storm Koppu in mountain areas may flood rivers and put hundreds of downstream villages at risk. Koppu was a category 4 typhoon when it made landfall, but it has weakened into a storm and has moved north over the Luzon Strait.

Houses, partially submerged in flood waters caused by heavy rains brought by Typhoon Koppu, are seen in City Camp Lagoon at Baguio city, north of ManilaHarley Palangchao/ReutersResidents are transported on an ice delivery vehicle along a flooded highway in Santa Rosa, Nueva EcijaErik de Castro/ReutersA billboard ripped in half by strong winds brought by Typhoon Koppu is seen along a main road in Quezon city, metro ManilaRomeo Ranoco/ReutersResidents wade through floodwaters in Candaba town, Pampanga provinceRomeo Ranoco/ReutersA woman stands inside her flooded house in Cabanatuan City, Nueva Ecija provinceErik de Castro/ReutersCesar Veloso, the father of Jane Veloso, on death row at an Indonesian prison, walks amongst mud-filled belongings in Cabanatuan City, Nueva Ecija provinceTed Aljibe/AFPPeople remove mud from outside their houses after heavy rains brought about by typhoon Koppu inundated homes in Cabanatuan City, Nueva Ecija provinceTed Aljibe/AFPRescue workers clear a fallen tree in Manila after it crushed a house, killing Ronel Castillo, a 14-year-old boy, and injuring four other peopleJay Directo/AFP

Residents of Cabanatuan City, one of the flooded areas in the rice-producing Nueva Ecija province, have begun clearing mud from their houses after water subsided. Even villages far from rivers in Nueva Ecija were flooded as water from the mountains came rushing down plains and valleys.

"We were not expecting this. Flood waters suddenly swelled around us so we evacuated to higher ground," said Reynato Simbulan, a village councillor who was among hundreds who fled to schools and village halls in Santa Rosa town in Nueva Ecija. "We're seven kilometres away from the river but we were still inundated," Simbulan said, adding that five-foot floods swept away farm animals and some houses made of light materials.

A man transports a pig across a flooded road in Santa Rosa, Nueva Ecija provinceErik de Castro/ReutersA pig and her piglets stay on higher ground after being rescued, in Santa Rosa, Nueva EcijaErik de Castro/ReutersA farmer checks a flooded rice field after heavy rains brought about by Typhoon Koppu inundated farms in Cabanatuan City, Nueva Ecija provinceTed Aljibe/AFPA farmer rides his water buffalo to higher ground at Barangay Camanutan, Isabela province, north of ManilaAFPDucklings swim towards a temporary pen as they are evacuated due to flooding in Jaen, Nueva EcijaErik de Castro/ReutersA motorised tricycle and several people are pulled on a farm tractor trailer along a flooded highway in Zaragoza, Nueva Ecija provinceErik de Castro/ReutersA boy plays on a flooded street in Jaen, Nueva Ecija provinceErik De Castro/ReutersResidents use a rope to board a truck while crossing floodwaters in Candaba town, Pampanga provinceRomeo Ranoco/ReutersResidents look at a snake swimming in floodwaters brought by Typhoon Koppu in Candaba town, Pampanga provinceRomeo Ranoco/ReutersResidents hold onto a rope while crossing floodwaters after Typhoon Koppu battered Candaba town, Pampanga provinceRomeo Ranoco/ReutersResidents push a tricycle taxi to higher ground along a flooded highway in Santa Rosa, Nueva Ecija provinceErik de Castro/ReutersA man paddles a makeshift raft made from banana tree trunks over a flooded rice field at Barangay Camanutan, Isabela provinceAFPResidents wade along a flooded highway in Santa Rosa town, Nueva Ecija provinceTed Aljibe/AFPResidents help each other cross a flooded road in Santa Rosa town, Nueva Ecija provinceTed Aljibe/AFP

At least 20 people were killed due to drowning, landslides, fallen trees and collapsed walls. The death toll may rise as several people are still reported missing. Koppu, Japanese for "cup," is the 12th storm this year to batter the Philippines, one of the world's most disaster-prone countries.